Improved some range check error messages.

Rev: src/array.c:1.147
Rev: src/builtin.cmod:1.136
Rev: src/builtin_functions.c:1.493
Rev: src/error.c:1.108
Rev: src/fd_control.c:1.48
Rev: src/opcodes.c:1.147
Rev: src/operators.c:1.179
Rev: src/stralloc.c:1.156